The present invention relates to a water treatment system and, more particularly, to a solid halogen feed system to supply treated water to a cooling water system.
Cooling water systems, such as cooling towers, are typically warm and provide an environment which is conducive to the growth of algae, bacteria, slime forming fungi and other slime forming organisms.
Water treatment systems are commonly used in cooling towers in order to control fouling caused by biological organisms which could result in inefficiencies in the cooling system. In the past, cooling systems utilizing chlorine, such as gaseous chlorine, have provided the principal method for controlling biological growth. Recently, alternative biocides have been considered in response to concerns relating to the environment, operator safety, and liability issues raised by the use of gaseous chlorine in water treatment systems.
It has been found that certain solid treatment products, for example halogens, provide an acceptable alternative biocide which meets the environmental and safety requirements while also effectively controlling the growth of biological organisms. Systems for feeding halogenated water to a water cooling tower generally feed the treated water to the cooling tower on a timed basis wherein a controller having a timer causes a valve to open, permitting water to flow from the cooling tower make-up source through the solid halogen feed system and back to the cooling tower according to predetermined time periods.
Such solid halogen treatment systems typically contain a quantity of the solid treatment product within a tank which must periodically be refilled to ensure that an effective amount of the product is present at all times. During a refilling operation, the tank is first partially drained of water and the treatment product is then poured in through an aperture in the top of the tank. In prior art treatment systems, it has been common practice to drain the tank to an outside location such as to the ground. This practice may result in a potential environmental discharge violation and is therefore undesirable.
Accordingly, there is a need for a treatment system using a solid treatment product contained within a tank wherein the tank is easily drained during a refilling operation and wherein the draining of the tank is done in an environmentally safe manner.